medication error, any incorrect or wrongful administration of a medication, such as a mistake in dosage or route of administration, failure to prescribe or administer the correct drug or formulation for a particular disease or condition, use of outdated drugs, failure to observe the correct time for administration of the drug, or lack of awareness of adverse effects of certain drug combinations. Causes of medication error may include difficulty in reading handwritten orders, confusion about different drugs with similar names, or lack of information about a patient’s drug allergies or sensitivities. When the nurse is in doubt, administration of a drug should be delayed until specifically authorized by a physician.